DCSBulkMeterDetails.py

import pythondcs  # From https://github.com/jarvisms/pythondcs
import csv  # Standard Library
dcs = pythondcs.DCSSession(DCSURL,USERNAME,PASSWORD)    # Credentials as needed

targets = [123,456,789]   # List of meters you want details for

with open(r"MetersDetails.csv", "w", newline="") as outputcsv:   # Adjust file as needed
  csvwriter = csv.writer(outputcsv)
  for id in targets:
    meter = dcs.get_meters(id)
    output = [
      meter["id"],
      meter["name"],
      meter["meterTypeName"],
      meter["serialNumber"],
      None,   # Deliberately leave a space for clarity
      "REGISTERS:",
      *[item for reg in meter["registers"] for item in (reg["id"], reg["name"], reg["unit"])],
        # The above line create 3 coloumns with reg-id, name and unit listed for each.
        # If there's only 1 register, jsut the 3 coloumns will be written.
        # If there are 10 registers, then there will be 30 coloumns.
    ]
    csvwriter.writerow(output)